At New Wave Flooring, we offer a wide range of composite decking options. To assist with your installation, we’ve prepared this guide. Please find the details below regarding the distance between joists:
Preparation is crucial for a successful composite decking installation. You must create a solid platform to which the decking boards will be attached using the clips and screws provided. This involves digging holes for the stumps, attaching the bearers to these stumps, and then connecting joists to the bearers to create a solid base for the composite decking boards. Refer to the chart below for the joist spacing requirements of each panel:
Size of board: Joist spacing requirement
138mm by 20mm by 5400mm solid: 400mm
138mm by 23mm by 5400mm hollow: 400mm
140mm by 20mm by 5400mm solid: 400mm
120mm by 20mm by 5400mm hollow: 200mm
HANDLING
Composite decking, compared to timber decking, has a higher specific density and is heavier. Please exercise caution when transporting and handling composite decking. Ensure it is stored and stacked on a flat surface prior to installation.
TOOLS
Standard carpentry tools are required, such as a power saw, string chalk lines, level, screwdriver, hammer, drill, and post hole digging tools, etc.
PREPARING THE FOUNDATION
A solid foundation is vital for the successful installation of any composite decking boards. Using a string line (or other devices), mark out the desired positions for the stumps, dig the holes, and set the stumps in concrete footings in preparation for attaching the bearers. It may be advisable to allow 24 hours for the concrete footings to cure.
JOISTS
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After constructing the subfloor bearers, attach the joists, ensuring the distance between the joists adheres to the guide provided above, depending on the type of composite decking board chosen. Screws or fixings used in the installation should be made of zinc, stainless steel, or a galvanized variety to prevent rust.
Please note: Composite decking is not suitable for use as structural components in any buildings. Do not fix composite decking directly onto any solid surface or water-tight system, such as concrete, rooftops, or balconies, etc.
Patterns recommended
3
Patterns not recommended
4
Please note: Composite decking is not suitable for use as structural components in any buildings. Do not fix composite decking directly onto any solid surface or water-tight system, such as concrete, rooftops, or balconies, etc.
EXPANSION AND SHRINKAGE OF BOARDS
Table 1: Gap requirement for a full length of 5.4m based on ambient temperature:
Temperature (°C)
Gap Requirement (mm)
0
9mm
10
7mm
20
5mm
30
3mm
40
0mm
You must allow sufficient gap when installing composite decking boards to accommodate thermal expansion and contraction. This is crucial not only when laying the boards end-to-end but also between the boards – width-to-width and end-to-width. Gapping allows for drainage and the slight thermal expansion and contraction of composite decking boards.
Width-to-Width: The general gapping is 2-5mm, determined by the clip size.
End-to-Width and End-to-End: The gap is determined by several factors including the length of the composite decking boards, the temperature at installation, the coefficient of thermal expansion/contraction, the highest temperature expected during the year, and whether the boards are exposed to full sun or shade. The expansion could be as much as 10mm at either end of the decking board, depending on these factors.
HOW TO INSTALL COMPOSITE DECKING
Installing the Bullnose Board:
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Secure the Starting Clips: Allow a 30mm distance to the edge if you don’t want any overhang. If you’re adding an upright facial board, move closer to the edge, depending on the thickness of the facial board you use.
Fix the Starting Clips on the Joist: Space them approximately 800mm to 1m apart, ensuring they are straight. It’s not necessary to place starting clips on every joist.
Install the Bullnose Board: Push the bullnose board down and forward to lock it into the starting clips.
Secure the Other Side: Use normal decking clips. You can also cut half the black clip off to allow you to slide the clips in between the decking groove and wall. Note: For plastic clips, screw only halfway down. DO NOT fully tighten to allow for temperature-induced length changes.
Continue attaching clips and screws to the joists as shown in the diagram, then slide the second board into place
